Margaret Carlson: Hey, Democrats, have you forgotten Joe Biden?

Vice President Joe Biden gestures after donning a pair of sunglasses May 17 as he delivers the Class Day Address at Yale University in New Haven, Conn.

Vice President Joe Biden gestures after donning a pair of sunglasses May 17 as he delivers the Class Day Address at Yale University in New Haven, Conn. (Jessica Hill, AP)

Opinion: Could Joe Biden run for President?

At Beau Biden's funeral on Saturday, President Barack Obama said his own family had become part of the Biden clan, playing by "Biden rules."

"We're always here for you," Obama said looking at Vice President Joe Biden and his family, giving them his "word as a Biden."

The president's poignant words brought comfort to a family suffering the grievous loss of a son, a brother and a husband at the age of 46. But the moment was also a reminder of how politicians sometimes view even those they purport to love as expendable. After all, Obama has treated his former secretary of state, Hillary Clinton, as his successor, even if he didn't squeeze her shoulders in the Biden style.

It's possible that before anointing Clinton, Obama and his vice president had The Talk, in which Biden confided he wasn't going to run, even though the official word is that Biden will decide this summer. It's to his credit that he didn't build his vice presidency around becoming president, but that doesn't mean Obama shouldn't have given him first crack at it. Still, Biden hasn't faltered in supporting the president. When he pledged his loyalty, he gave his word as a Biden.

It's understandable that Obama, the Washington power crowd and the Democratic base would pick Hillary over Joe — the money, the machine and the early polls pointed to a strife-free coronation.

Yet there's a long way left to go in the 2016 presidential campaign. Even as Hillary's performance puzzles, her poll numbers soften and the public's perception of her honesty and trustworthiness sink below 50 percent, people still anxiously cling to her as the only viable candidate. It's hard to see how they could look at Biden and not see one.

Obama saw an asset in Biden's experience as two-time chairman of the Senate Foreign Relations Committee and needed the political capital from his 40 years in Congress. The president leaned heavily on his wingman in managing the U.S. troop withdrawals from Iraq and Afghanistan, coping with the crisis in Ukraine after the failure of Clinton's reset with Vladimir Putin, and overseeing the $787 billion economic stimulus package. Biden is often the "last person" in the room when a big decision is being made.

In some ways, Biden is the anti-Obama, and maybe his perfect complement. The vice president has an ample gift for the kind of politics Obama can't stomach — the shooting the breeze, the backslapping and, yes, even the shoulder squeezing. At the White House Correspondents Dinner in 2013, Obama defended his aloofness. "Some folks still don't think I spend enough time with Congress. 'Why don't you get a drink with Mitch McConnell?' they ask," Obama said. "Really? Why don't you get a drink with Mitch McConnell?"

Well, Joe might not want to, but he would. Biden worked tirelessly negotiating fiscal agreements with McConnell and smoothing relations with congressional Democrats and the Democratic base. He makes nice with reporters every summer, drenching them with a Super Soaker at a picnic at his residence.

It's true, Biden does sometimes come off as impulsive as a Saint Bernard, blurting out things you can bet he wished he hadn't. After Republican presidential nominee Mitt Romney's "47 percent" gaffe in 2012, Biden told a black audience they'd be back in chains if Romney won.

When Obama notes the difference between him and Biden, it's often as a laugh line. After a drone buzzed the White House, Obama joked that Joe raced outside with a bat trying to bring it down.

But the image of Joe trying to protect the White House goes to the mystery of how he keeps up his enthusiasm for the often thankless work of politics after all these years and how he maintains his enviable love of life after so much heartbreak.

Before the untimely death of his son, he endured the death of his 1-year old daughter and wife in a car accident at Christmas time in 1972. Biden himself almost died after a brain aneurysm in 1988 that took him out of public life for seven months.

A few more blunders as the price for more of him could be a fair trade. Not one Republican presidential candidate has his experience or his heart — nor, for that matter, does the presumptive Democratic nominee, Hillary Clinton.

Obama, who said in his eulogy for Beau Biden on Saturday, "Joe, you are my brother, and I am grateful every day you have got such a big heart, and a big soul, and those broad shoulders," might see this now. Even the cool and disciplined Obama couldn't miss Biden's steely core and his character as he stood for 10 hours shaking hands and embracing the thousands of Delaware residents who waited in long lines to pay their respects to him and his son.

The priceless value of Biden has long been in plain sight. Obama was finally moved to emulate him. On Saturday, the president did what Joe would do. He didn't just hug the weeping vice president. He kissed him.